[GRASS-dev] r.shrink??

[Jarek Jasiewicz]

Michael Barton pisze:
> Thanks. Of course this only works for maps with raster areas surrounded by nulls.
>
> Michael
> ____________________
> C. Michael Barton
> Director, Center for Social Dynamics & Complexity 
> Professor of Anthropology, School of Human Evolution & Social Change
> Arizona State University
>
> voice: 	480-965-6262 (SHESC), 480-727-9746 (CSDC)
> fax:          480-965-7671 (SHESC),  480-727-0709 (CSDC)
> www: www.public.asu.edu/~cmbarton, http://csdc.asu.edu
>
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> On May 26, 2010, at 1:03 PM, Jarek Jasiewicz wrote:
>
>   
>> Michael Barton pisze:
>>     
>>> Am I missing something or is there no module that does the opposite of 
>>> r.grow (i.e., shrink rasters of a given category by 1 or more pixels)? 
>>> r.thin tries to thin to a line.
>>>
>>> Michael
>>> ____________________
>>> C. Michael Barton
>>> Director, Center for Social Dynamics & Complexity 
>>> Professor of Anthropology, School of Human Evolution & Social Change
>>> Arizona State University
>>>
>>> voice:  480-965-6262 (SHESC), 480-727-9746 (CSDC)
>>> fax:          480-965-7671 (SHESC),  480-727-0709 (CSDC)
>>> www: www.public.asu.edu/~cmbarton, 
>>> <http://www.public.asu.edu/%7Ecmbarton,> http://csdc.asu.edu
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
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>> for that I use following mapcalc expression:
>>
>> echo 'map=if(  isnull(map[-1,-1])||isnull(map[-1,0])|| \
>> isnull(map[-1,1])||isnull(map[0,-1])|| \
>> isnull(map[0,1])||isnull(map[1,-1])||isnull(map[1,0])|| \
>> isnull(map[1,1]), map,null())'| r.mapcalc
>>
>> this work for me
>> Jarek
>>
>>
>>     
not only:
...map[-1,1]==0... or any other background

J.